This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A377561 #9 Nov 04 2024 11:13:32 %S A377561 8,13,62,78,113,125,132,157,207,230,315,337,428,473,493,570,652,763, %T A377561 788,902,928,932,987,1075,1113,1135,1147,1158,1225,1245,1322,1327, %U A377561 1387,1432,1483,1602,1607,1672,1702,1753,1767,1845,1880,1973,1992,2083,2155,2212,2220,2233 %N A377561 Numbers k such that 24k - 1 and 24k + 1 are a pair of twin primes in A115591. %C A377561 Numbers k such that 24k - 1 is in A367318. Note that all terms there are congruent to 23 modulo 24. %H A377561 Jianing Song, <a href="/A377561/b377561.txt">Table of n, a(n) for n = 1..10000</a> %F A377561 a(n) = (A367318(n) + 1)/24. %e A377561 8 is a term since the multiplicative order of 2 modulo 24*8 - 1 = 191 is 95, and the multiplicative order of 2 modulo 24*8 + 1 = 193 is 96. %o A377561 (PARI) isA377561(k) = znorder(Mod(2, 24*k-1))==12*k-1 && znorder(Mod(2, 24*k+1))==12*k \\ No need to check primality as the multiplicative order of 2 modulo a composite odd number m cannot be equal to (m-1)/2; see my comment in A001567 %Y A377561 Cf. A115591, A002822, A367318, A319250. %K A377561 nonn %O A377561 1,1 %A A377561 _Jianing Song_, Nov 01 2024